The Germans conquer Alsace, and they require everyone to take a German name. A German soldier goes up to a farmer by the name of Lagarde and informs him of the requirement.
Lagarde refuses, arguing as follows:
Look, 'Lagarde' in German would become 'Wache'.1In a few years, the way these things go, French will reconquer Alsace, and then I'll have to go by 'Vache'.2
Then you guys will come back and make me change 'Vache' to 'Kuh'.3
Then the French will come back and make 'Kuh' into 'Cul'.4
Then you Germans will come back and make me change 'Cul' to 'Arschloch'.5
So why don't you just call me 'Arschloch' from the get go?
1. La garde in French means 'the sentry', which translates into German Wache 'sentry'.
2. French speakers would pronounce Wache to sound like vache, the French word for 'cow'.
3. The German word for 'cow' is Kuh.
4. French speakers would pronounce Kuh to sound basically the same as cul '(ass)hole'.
5. The German word for 'asshole' is Arschloch.